[src/trunk]: src/usr.sbin/bta2dpd/bta2dpd Add thottling when playing from file.

[nat <nat%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/32a4ff095cf3
branches:  trunk
changeset: 378099:32a4ff095cf3
user:      nat <nat%NetBSD.org@localhost>
date:      Thu Jul 20 12:33:27 2023 +0000

description:
Add thottling when playing from file.

This avoids rapid playback when playing from file with affected devices.

Playback using pad(4) is still preferred ad gives a better result.
Playback from pad(4) is unaffected by this change.

XXX pullup-10.

diffstat:

 usr.sbin/bta2dpd/bta2dpd/sbc_encode.c |  23 ++++++++++++++++++++++-
 1 files changed, 22 insertions(+), 1 deletions(-)

diffs (75 lines):

diff -r f360b3af73a9 -r 32a4ff095cf3 usr.sbin/bta2dpd/bta2dpd/sbc_encode.c
--- a/usr.sbin/bta2dpd/bta2dpd/sbc_encode.c     Thu Jul 20 11:59:04 2023 +0000
+++ b/usr.sbin/bta2dpd/bta2dpd/sbc_encode.c     Thu Jul 20 12:33:27 2023 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: sbc_encode.c,v 1.11 2023/05/28 07:59:17 mlelstv Exp $ */
+/* $NetBSD: sbc_encode.c,v 1.12 2023/07/20 12:33:27 nat Exp $ */
 
 /*-
  * Copyright (c) 2015 - 2016 Nathanial Sloss <nathanialsloss%yahoo.com.au@localhost>
@@ -32,6 +32,7 @@
  */
 
 #include <sys/cdefs.h>
+#include <sys/time.h>
 #include <sys/types.h>
 #include <sys/param.h>
 #include <errno.h>
@@ -841,6 +842,7 @@ stream(int in, int outfd, uint8_t mode, 
     blocks, uint8_t alloc_method, uint8_t bitpool, size_t mtu, int volume)
 {
        struct rtpHeader myHeader;
+       struct timeval myTime;
        uint8_t *whole, *frameData;
        int16_t music[2048];
        ssize_t len, mySize[16], offset, next_pkt;
@@ -849,6 +851,7 @@ stream(int in, int outfd, uint8_t mode, 
        size_t frequency;
        static size_t ts = 0;
        static uint16_t seqnumber = 0;
+       static time_t prevTime, readTime, sleepTime, timeNow;
        int numpkts, tries;
 
        global_mode = mode;
@@ -912,9 +915,11 @@ stream(int in, int outfd, uint8_t mode, 
        next_pkt = 0;
        len = 0;
        pkt_len = 80;
+       readTime = 0;
        while (totalSize + ((size_t)pkt_len * 2) <= mtu) {
 
                len = readloop(in, music, readsize);
+               readTime += (time_t)readsize;
                if (len < (int)readsize)
                        break;
 
@@ -934,6 +939,8 @@ stream(int in, int outfd, uint8_t mode, 
                return -1;
        }
 
+       readTime = readTime * 1000000 / 2 / global_chan / (time_t)frequency;
+
        myHeader.numFrames = (uint8_t)numpkts;
        whole = malloc(totalSize);
        if (whole == NULL)
@@ -946,6 +953,20 @@ stream(int in, int outfd, uint8_t mode, 
        free(frameData);
 
        tries = 1;
+
+       /* Wait if necessary to avoid rapid playback. */
+       gettimeofday(&myTime, NULL);
+       timeNow = myTime.tv_sec * 1000000 + myTime.tv_usec;
+       if (prevTime == 0)
+               prevTime = timeNow;
+       else
+               sleepTime += readTime - (timeNow - prevTime);
+       if (sleepTime >= 1000) {
+               usleep(500);
+               sleepTime -= 1000;
+       }
+       prevTime = timeNow;
+
 send_again:
        len = write(outfd, whole, totalSize);